This invention relates generally to flow cytometry and, more specifically, to devices and methods for aligning a flow cytometry detection system.
Flow cytometry is a valuable method for the analysis and isolation of biological particles such as cells and constituent molecules. As such it has a wide range of diagnostic and therapeutic applications. The method utilizes a fluid stream to linearly segregate particles such that they can pass, single file, through a detection apparatus. Individual cells can be distinguished according to their location in the fluid stream and the presence of detectable markers. Thus, a flow cytometer can be used to produce a diagnostic profile of a population of biological particles. For example, flow cytometry has been used to measure the decline or maintenance of immune cells during the course of treatment for HIV infection and to determine the presence or absence of tumor cells for prognosis and diagnosis of cancer patients.
Isolation of biological particles has been achieved by adding a sorting or collection capability to flow cytometers. Particles in a segregated stream, detected as having one or more desired characteristics, are individually isolated from the sample stream by mechanical or electrical removal. This method of flow sorting has been used to separate sperm bearing X and Y chromosomes for animal breeding, to sort chromosomes for genetic analysis, to isolate cells bearing specific antigens and to identify new organisms from complex biological populations. Although sorting capability can slow down the rate of sample analysis by a cytometer, cell sorters can be operated at rates allowing sorting of greater than 100,000 events per second.
Although an operating flow cytometer can detect and sort hundreds of thousands of cells per second, a true estimate of the throughput and efficiency of the instrument must include the time and effort required to prepare the instrument before and between sample runs. Specifically, any down time experienced by the instrument must be factored into an evaluation of the instruments performance and throughput across a typical workday. For example, time spent adjusting a clinical instrument between analyses of patient samples will reduce the number of patients that can be diagnosed in a typical work day and increase the amount of time the patients and their medical practitioners must wait for a diagnosis.
For an instrument having the precision to detect or sort through over 100,00 events in a second, alignment of the detector must be diligently attended to. Currently, the flow cytometers used in laboratory and clinical settings require manual monitoring and alignment procedures to maintain the needed precision. Realigning a detector between sample runs can require significant time and effort even for a highly trained technician. This is time that can be costly for those operating the instrument and those relying upon its diagnosis.
Thus, there exists a need for a device which allows efficient monitoring and aligning of detector systems used in flow cytometry. The present invention satisfies this need and provides related advantages as well.